The floors in my 29-year-old house have areas that squeak, and there seem to be more every day. Most of the flooring is carpeted. What can be done to correct this problem? — Angie's List member Mary Jane Pfuetze

Squeaks are usually caused by loose subfloors, according to Vasile Contra, owner of highly rated CV Hardwood Flooring in Chicago, which was selected as one of Chicago's Best Contractors by Angie's List Magazine in 2009. "Many of them were nailed down, and movement makes the subfloor go up and down as it ages," he says. "The solution is to remove the floor, reglue the subfloor, screw it to the joists, and reinstall the old floor."

Contra cautions that doing the job correctly - and safely - will always involve pulling up the wood. "You don't want to shoot through a gas line or an electric line," he says. The work is easier on carpeted floors, since there's no hardwood to pull up.

Some older homes have sleeper subfloors, according to Contra and Adam Pat, owner of highly rated A Floor Clinic in Chicago. "This is when perpendicular boards run between the hardwood and the subfloor, 12 to 16 inches apart," Pat says. "Usually these boards are only nailed, so they or the subfloor could make the squeaks."

Pat also says the only certain way to get rid of squeaks is to replace the subfloor with plywood and screw it down. "You could drive screws through individual points, but you'd be pulling up a lot of wood to get to them, and there's no way to be sure you'd get all the squeaks," he says. "But that would be a less expensive option for high-traffic areas."